Formula to find duplicate values in one column

Hello
Apologies if this has been posted before.
I have a long spreadsheet of data with name and surname in one column (column A). What is the easiest way to find duplicate names and surnames in that column?
If posted before, could you pls fwd me the link?
Thank you

=IF(COUNTIF($A$2:$A$15,A2)=1,FALSE,NOT(COUNTIF($A$2:A2,A2)=1))

used as a conditonal formatting formula should highlight all duplicates (2nd and subsequent occurrences). If that is't what you need, then please be more exact in your description!

Maybe something like this...

Data Range

	A	B
1	Header	Header
2	Name1
3	Name1	Dup
4	Name7
5	Name7	Dup
6	Name5
7	Name7	Dup
8	Name1	Dup
9	Name4
10	Name4	Dup

This formula entered in B2 and copied down:

=IF(ROW()<>MATCH(A2,A:A,0),"Dup","")

Odd. It was working OK in the attached file. did you adjust the formula ranges to suit your actual data?

If you would rather have the duplicates highlighted...

Data Range

	A
1	Header
2	Name1
3	Name1
4	Name7
5	Name7
6	Name5
7	Name7
8	Name1
9	Name4
10	Name4

Select the ENTIRE range A2:A10 starting from cell A2.
Cell A2 will be the active cell. The active cell is the
one cell in the selected range that is not shaded. The
formula will be relative to the active cell.

Goto the Home tab>Styles>Conditional Formatting>
Manage rules>New rule>Use a formula to determine
which cells to format

Enter this formula in the box below:

=ROW()<>MATCH(A2,A:A,0)

Click the Format button
Select the desired fill color
OK out

You're welcome. Thanks for the feedback!